J1 should give you access to the primary serial port, most likely at v3.3 signal levels.

The regular TeraStation was equiped with a normal micro-ATX powersupply and has an ATX powerconnector on the mainboard. For the Pro this have been replaced by a custom powersupply with an proprietary connector (lower right, CN13).

The resetbutton has not been populated, but it's functionality is most likely provided by the LCD pannel. The LCD pannel is connected via CN? a 15 (or 16) pin connector on the bottom right edge.

The 3 pin connector next to it looks like a regular fan connector and most likely controlls the system fan.

The big 8pin connector CN16 provieds power to the harddisks.

Special thanks go to User:MikeSchinkel for providing my with 30 images of his TSpro internals, what allowed me to do this writeup.